Passage of Phosphorus-free Lawn Fertilizer Laws by U.S. States

Abstract

Abstract Phosphorus (P) is an essential plant nutrient, but it can pollute rivers and lakes. State laws banning P in lawn fertilizer can reduce pollutant loads from urban areas. A random effects panel probit model using nationwide data from various sources was estimated to analyze factors affecting passage of these laws. To test hypotheses regarding alternative theories, we incorporated variables relating to public interest, private interest, ideology, and diffusion literatures and found support for all of them. States with higher percentages of water area were more likely to pass P-free laws, as were those with higher percentages of employment in water-related industries. Surprisingly, states with more fertilizer companies were more likely to pass P-free laws, but the effect was quadratic. We found an S-shaped diffusion curve as a function of time. No laws have been passed since 2013, when Scotts dropped P from their Turf Builder fertilizers.